Emiliano Zapata Wastewater Treatment Plant, Zacatecas, Mexico

The Emiliano Zapata wastewater treatment plant is located in the community of Emiliano Zapata (San José) within the municipality of Sain Alto, Zacatecas, Mexico. This facility serves a population of 1,643 residents, making it a small-scale municipal plant in a rural inland setting. The plant operates with secondary treatment, which is the standard level required under Mexican regulations (NOM-001-SEMARNAT-1996) for discharges to national waters. It has a designed capacity of 197.86 cubic meters per day and currently treats approximately 155.52 cubic meters per day, indicating it is operating below its design capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into local water bodies that eventually drain into the Rio Grande de Santiago basin, which flows westward to the Pacific Ocean. The plant plays a key role in protecting local water quality and downstream ecosystems in the semi-arid region of Zacatecas, where water resources are critical for agriculture and community use.

The plant discharges into local streams that are part of the Rio Grande de Santiago watershed, which ultimately drains into the Pacific Ocean via the Rio Santiago. This region of Zacatecas is semi-arid, and water bodies are ecologically sensitive due to limited water availability. The treated effluent helps maintain base flows and supports aquatic life in downstream habitats, including fish and migratory bird species that rely on these watercourses.